Since King Bhumibol's death, there has been an increase in mob activity. Online zealots have been searching the internet, determined to punish anyone perceived to have insulted the monarchy.

For Thailand's royalists, King Bhumibol Adulyadej will be remembered as a potent, father-like figure who guided them through turbulent decades. He became an example of peace and worked hard to improve the conditions of the poor in the country.

Thais have been urged to name and shame those who defame the monarchy, Justice Minister Paiboon Koomchaya, said on Tuesday, after fresh videos emerged of mob justice against people accused of insulting the institution.

The death of Thailand's most beloved King has sparked widespread grief in the nation. But it has also unleashed a growing number of cases of vigilantism by royalists: Thais against people accused of insulting the monarchy. Thailand's monarchy is protected by a draconian law that outlaws criticism with punishments of up to 15 years in jail for each insult.

"There is no better way to punish these people than to socially sanction them," Paiboon told reporters, as he vowed to "pursue those people who violate the law."

A video widely shared on social media showed an elderly woman on a Bangkok bus being berated by fellow commuters in the presence of police.

As she exits the bus, the woman is slapped in the face by another woman dressed in black. It is not clear when the incident took place but the video was uploaded on Monday evening.

Black-shaming

Hard-line royalists have also taken to social media calling for vigilante action against alleged transgressors, who insult the monarchy or the state.

On Sunday, a woman on Samui island was forced by police to kneel below a portrait of King Bhumibol in front of a baying mob after she allegedly posted an insulting comment about the monarchy on Facebook.

She has since been charged with lese majeste ­­–- the law that makes it a crime to offend or insult the dignity of a reigning sovereign or state.

Other social media users have berated those deemed not to be mourning sufficiently deeply or failing to wear black clothes.

The phenomenon dubbed "black-shaming" has been condemned by the government.

Media inside Thailand, both local and foreign, must heavily self-censor.

Authorities, however, struggle to censor critics or media based overseas.

But Paiboon said the government would renew extradition requests for Thais abroad -- something that is unlikely to sway governments in countries where lese majeste is not a crime.